1. Field of the Invention
The present invention relates to radio telephone systems such as car telephone systems and more particularly, to a radio telephone system wherein a communicating party being asked to hold on can prompt a user of the radio telephone system to release a hold state.
2. Description of the Related Art
A car telephone system has been conventionally provided with a hold function to secure driver's safety and to prevent a secret talk with the party from being leaked.
When the user sets such a car telephone system in its hold state, both send and receive voices at the side of the party are muted and the user side transmits a hold tone indicative of the hold state to the party.
In the hold state, however, there is a problem that when the hold time is long, the party has no chance to contact the user during the hold time and has to just wait patiently.
For the purpose of eliminating the problem, it has been considered to allow the party to be able to send his voice to the user side in the hold state. Even in this case, however, the user undersirably hears the party's voice which is noisy.
The prior art car telephone system also has a problem that when the hold time becomes long in the hold state, the waiting time of the party becomes long and the party may become irritated because of the absence of any means to prompt the user to release the hold state.